Distinctive Features of Phase Transitions in Pb10−xCux(PO4)6O and Cu2S

This paper argues the copper sulfide theory of LK-99's phase transition. The LK-99's transition changes with the applied current, while copper sulfide's phase transition is solely determined by temperature. If one wants to claim that LK-99's phase transition is like copper sulfide, they must demonstrate that applying current to copper sulfide causes its phase transition temperature to change by the same amount as in LK-99. As of now, no such evidence has been found.

However, if there is an error in the way temperature is applied when creating the LK-99 current-voltage graph (measurement error), the internal part of the sample may reach the critical temperature due to Joule Heating caused by the current, but this internal heat may not be effectively transferred to the external environment, leading to a temperature difference. (This is what Dr. Hong has argued.) In other words, even copper sulfide might appear to exhibit a change in phase transition temperature depending on the applied current (since the temperature sensor measures only the external temperature). Therefore, if one assumes that quantum has made a mistake, it must be disproven.